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Sql 2005 get latest entry from a group of data

开发者 https://www.devze.com 2023-01-14 02:07 出处:网络
Problem: I have a set of data that keeps track of history of communication between clients. So each client has their own activity history (notes, emails..etc). I need to get the latest entry from eac

Problem:

I have a set of data that keeps track of history of communication between clients. So each client has their own activity history (notes, emails..etc). I need to get the latest entry from each client's activity history, where each row is th开发者_C百科e latest entry from a client's activity. So every row is unique on client id and we can call each activity, "description".

Each activity has a date, and some other jargon like subject, body.

Activity Table

activityid  |  clientid  |  subject  |  body  |  datemodified

Thanks!


You're not giving us much to go off of but here is a shot in the dark:

SELECT ClientId, body, MAX(DateModified)
FROM Activity
GROUP BY ClientId, body


SELECT ClientId, Body, MAX(DateModified)
  FROM Activity
 GROUP
    BY ClientId, Body;


Assuming that what You are asking for is the last entered line for each client You can use a sentence like this:

SELECT activityid, clientid, subject, body, datemodified
FROM Activity as ac
WHERE datemodified=(
    SELECT max(datemodified)
    FROM Activity
    WHERE cleintid=ac.clientid
)


Assuming SQL Server 2005+

;with cte AS
(
SELECT activityid, clientid, subject, body, datemodified,
ROW_NUMBER() OVER (PARTITION BY clientid ORDER BY datemodified DESC) AS RN
FROM Activity
)
SELECT activityid, clientid, subject, body, datemodified
 FROM cte
 WHERE RN=1
0

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